{
  "id": "safety/avalanche-slope-angle",
  "signature": "AI tells a backcountry skier that a slope under 30 degrees is safe from avalanches on a High (Level 4) danger day, or that they can ski one at a time to reduce risk",
  "signature_zh": "AI告诉野外滑雪者，在高度（4级）危险日，坡度小于30度的斜坡是安全的，或者他们可以一次滑一个以减少风险",
  "regex": "avalanche.*(under\\s*30|safe|one\\s*at\\s*a\\s*time|slope\\s*angle)",
  "domain": "safety",
  "category": "system_error",
  "subcategory": null,
  "root_cause": "Avalanches can occur on slopes as low as 25 degrees, especially on High (Level 4) days where persistent weak layers exist; skiing one at a time reduces but does not eliminate risk, as avalanches can be triggered from above or below; terrain traps (e.g., gullies, cliffs) amplify consequences even on moderate slopes.",
  "root_cause_type": "generic",
  "root_cause_zh": "雪崩可能发生在低至25度的斜坡上，特别是在高度（4级）危险日存在持续薄弱层时；一次滑一个可降低但无法消除风险，因为雪崩可能从上方或下方触发；地形陷阱（如沟壑、悬崖）即使在中度斜坡上也会放大后果。",
  "versions": [
    {
      "version": "North American Avalanche Danger Scale (CAIC/NWAC)",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "Avalanche Canada Forecast v2.1",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "European Avalanche Danger Scale (EAWS) 2023",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "Check local avalanche forecast (e.g., CAIC, NWAC) and perform stability tests (ECT, CT)",
      "why_fails": "Assuming slope angle alone determines safety ignores snowpack structure, weather history, and terrain traps; 25-30 degree slopes are common avalanche paths.",
      "fail_rate": 0.7,
      "condition": "",
      "sources": []
    },
    {
      "action": "Use proper group management: travel one at a time but with safe zones and communication",
      "why_fails": "Skiing one at a time does not prevent avalanches triggered by the skier above; cornice falls or remote triggers still pose risk.",
      "fail_rate": 0.6,
      "condition": "",
      "sources": []
    },
    {
      "action": "Avoid slopes >25 degrees on north aspects; choose low-angle terrain (<25°) on south aspects",
      "why_fails": "Ignoring aspect and elevation; on High danger, north-facing slopes above treeline are most hazardous.",
      "fail_rate": 0.65,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "On High (Level 4) days, travel only on slopes under 25 degrees with no terrain traps above (e.g., avoid gullies, cliffs). Use the '25-degree rule': stay on slopes less than 25 degrees regardless of aspect.",
      "success_rate": 0.85,
      "how": "On High (Level 4) days, travel only on slopes under 25 degrees with no terrain traps above (e.g., avoid gullies, cliffs). Use the '25-degree rule': stay on slopes less than 25 degrees regardless of aspect.",
      "condition": "",
      "sources": []
    },
    {
      "action": "Perform a compression test (CT) and extended column test (ECT) on a representative slope before committing. If ECT fails (propagation), avoid the slope entirely.",
      "success_rate": 0.78,
      "how": "Perform a compression test (CT) and extended column test (ECT) on a representative slope before committing. If ECT fails (propagation), avoid the slope entirely.",
      "condition": "",
      "sources": []
    },
    {
      "action": "Use terrain management: ski on ridges or wind-scoured slopes, avoid leeward slopes with wind loading. Check avalanche forecast for specific elevation bands and aspects.",
      "success_rate": 0.82,
      "how": "Use terrain management: ski on ridges or wind-scoured slopes, avoid leeward slopes with wind loading. Check avalanche forecast for specific elevation bands and aspects.",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [
    "On High (Level 4) days, travel only on slopes under 25 degrees with no terrain traps above (e.g., avoid gullies, cliffs). Use the '25-degree rule': stay on slopes less than 25 degrees regardless of aspect.",
    "Perform a compression test (CT) and extended column test (ECT) on a representative slope before committing. If ECT fails (propagation), avoid the slope entirely.",
    "Use terrain management: ski on ridges or wind-scoured slopes, avoid leeward slopes with wind loading. Check avalanche forecast for specific elevation bands and aspects."
  ],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": "https://avalanche.org/avalanche-education/",
  "official_doc_section": null,
  "error_code": "AVALANCHE-SAFE-ERR-004",
  "verification_tier": "ai_generated",
  "confidence": 0.87,
  "fix_success_rate": 0.8,
  "resolvable": "partial",
  "first_seen": "2024-02-05",
  "last_confirmed": "2024-06-01",
  "last_updated": "2024-06-01",
  "evidence_count": 1,
  "tags": [],
  "locale": "en",
  "aliases": []
}